We consider integral transforms that can describe ideal imaging optical systems with circular impulse response. The integral transform, referred to as the Circular Radon transform (CRT), is considered as an average taken along all circumferences offixed radius on the plane. The CRT can be optically realized using a Fourier correlator with amplitude filter, with its transmittance function being proportional to the Bessel function of zero order. Also, a mesooptics transform (MT) is considered that can be optically re*alized using a Fourier correlator with axicon in the spatial-frequency plane. An ability of applying the CRT to realize traditional Radon transform optically has been tested.